Re: [patch] package.mk: use cp without -p if it fails

["Amitai Schleier" <schmonz%schmonz.com@localhost>]

On 5 Aug 2021, at 15:47, Sijmen J. Mulder wrote:

> After setting up pkgsrc on a new FreeBSD 13 installation on ZFS, I
> encoutnered an error when building any package: cp would report a
> chattr failure copying the package file from the work directory to the
> packages directory.
>
> This was because my work directory is hosted on the ZFS root
> filesystem, which sets 'uarch' flags, and the packages directory is on
> an NFS-mounted volume which doesn't support that flag (or any?).
>
> The attached patch uses regular 'cp' if 'cp -p' doesn't work.

I'd like to get review on my (similar but different) patch, below. It's 
served me well for quite some time.

-----

I export pkgsrc over NFS from a macOS host to a variety of VMs, each of
which sets ${PACKAGES} to a subdir of ${PKGSRCDIR}/packages (on the same
NFS mount) so that the generated packages all land in one place.

From my Debian, Devuan, Ubuntu, and CentOS 8 (but not 7) VMs,
copying ${STAGE_PKGFILE} to ${PKGFILE} fails to preserve permissions,
which fails the copy and the "package" target with it. The error
looks like so:

===> Building binary package for foo-4.2
=> Creating binary package 
/home/schmonz/trees/pkgsrc-cvs/packages/Debian/All/foo-4.2.tgz
/bin/cp: preserving permissions for 
‘/home/schmonz/trees/pkgsrc-cvs/packages/Debian/All/foo-4.2.tgz’: 
Operation not permitted

Assuming permissions on built packages are merely a nice-to-have, avoid
failing if we couldn't preserve them, while making sure to still fail if
package _contents_ weren't copied byte-for-byte.

Index: mk/pkgformat/pkg/package.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/pkgformat/pkg/package.mk,v
retrieving revision 1.16
diff -u -r1.16 package.mk
--- mk/pkgformat/pkg/package.mk	19 Aug 2017 00:30:19 -0000	1.16
+++ mk/pkgformat/pkg/package.mk	27 Nov 2021 21:35:40 -0000
@@ -66,7 +66,8 @@
 	@${STEP_MSG} "Creating binary package ${.TARGET}"
 	${RUN} ${MKDIR} ${.TARGET:H};					\
 	${LN} -f ${STAGE_PKGFILE} ${PKGFILE} 2>/dev/null ||		\
-		${CP} -pf ${STAGE_PKGFILE} ${PKGFILE}
+		${CP} -pf ${STAGE_PKGFILE} ${PKGFILE} 2>/dev/null ||	\
+		${CMP} ${STAGE_PKGFILE} ${PKGFILE}
 .endif

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